#! /usr/bin/python2.4

#

# CDDL HEADER START

#

# The contents of this file are subject to the terms of the

# Common Development and Distribution License (the "License").

# You may not use this file except in compliance with the License.

#

# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

# or http://www.opensolaris.org/os/licensing.

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# file and include the License file at usr/src/OPENSOLARIS.LICENSE.

# If applicable, add the following below this CDDL HEADER, with the

# fields enclosed by brackets "[]" replaced with your own identifying

# information: Portions Copyright [yyyy] [name of copyright owner]

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#

# Copyright 2009 Sun Microsystems, Inc.  All rights reserved.

# Use is subject to license terms.

#

"""This module provides utility functions for ZFS.

zfs.util.dev -- a file object of /dev/zfs """

import gettext

import errno

import os

# Note: this module (zfs.util) should not import zfs.ioctl, because that

# would introduce a circular dependency

errno.ECANCELED = 47

errno.ENOTSUP = 48

dev = open("/dev/zfs", "w")

_ = gettext.translation("SUNW_OST_OSLIB", "/usr/lib/locale",

    fallback=True).gettext

def default_repr(self):

	"""A simple __repr__ function."""

	if self.__slots__:

		str = "<" + self.__class__.__name__

		for v in self.__slots__:

			str += " %s: %r" % (v, getattr(self, v))

		return str + ">"

	else:

		return "<%s %s>" % \

		    (self.__class__.__name__, repr(self.__dict__))

class ZFSError(StandardError):

	"""This exception class represents a potentially user-visible

	ZFS error.  If uncaught, it will be printed and the process will

	exit with exit code 1.

	errno -- the error number (eg, from ioctl(2))."""

	__slots__ = "why", "task", "errno"

	__repr__ = default_repr

	def __init__(self, eno, task=None, why=None):

		"""Create a ZFS exception.

		eno -- the error number (errno)

		task -- a string describing the task that failed

		why -- a string describing why it failed (defaults to

		    strerror(eno))"""

		self.errno = eno

		self.task = task

		self.why = why

	def __str__(self):

		s = ""

		if self.task:

			s += self.task + ": "

		if self.why:

			s += self.why

		else:

			s += self.strerror

		return s

	__strs = {

		errno.EPERM: _("permission denied"),

		errno.ECANCELED:

		    _("delegated administration is disabled on pool"),

		errno.EINTR: _("signal received"),

		errno.EIO: _("I/O error"),

		errno.ENOENT: _("dataset does not exist"),

		errno.ENOSPC: _("out of space"),

		errno.EEXIST: _("dataset already exists"),

		errno.EBUSY: _("dataset is busy"),

		errno.EROFS:

		    _("snapshot permissions cannot be modified"),

		errno.ENAMETOOLONG: _("dataset name is too long"),

		errno.ENOTSUP: _("unsupported version"),

		errno.EAGAIN: _("pool I/O is currently suspended"),

	}

	__strs[errno.EACCES] = __strs[errno.EPERM]

	__strs[errno.ENXIO] = __strs[errno.EIO]

	__strs[errno.ENODEV] = __strs[errno.EIO]

	__strs[errno.EDQUOT] = __strs[errno.ENOSPC]

	@property

	def strerror(self):

		return ZFSError.__strs.get(self.errno, os.strerror(self.errno))

def nicenum(num):

	"""Return a nice string (eg "1.23M") for this integer."""

	index = 0;

	n = num;

	while n >= 1024:

		n /= 1024

		index += 1

	u = " KMGTPE"[index]

	if index == 0:

		return "%u" % n;

	elif n >= 100 or num & ((1024*index)-1) == 0:

		# it's an exact multiple of its index, or it wouldn't

		# fit as floating point, so print as an integer

		return "%u%c" % (n, u)

	else:

		# due to rounding, it's tricky to tell what precision to

		# use; try each precision and see which one fits

		for i in (2, 1, 0):

			s = "%.*f%c" % (i, float(num) / (1<<(10*index)), u)

			if len(s) <= 5:

				return s

def append_with_opt(option, opt, value, parser):

	"""A function for OptionParser which appends a tuple (opt, value)."""

	getattr(parser.values, option.dest).append((opt, value))